/**
 * \file aes.h
 *
 * \brief AES block cipher
 *
 *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
 *
 *  This file is part of mbed TLS (https://polarssl.org)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef KFPOLARSSL_AES_H
#define KFPOLARSSL_AES_H

#include <string.h>

#ifdef _MSC_VER
#include <basetsd.h>
typedef UINT32 uint32_t;
#else
#include <inttypes.h>
#endif

#define AES_ENCRYPT 1
#define AES_DECRYPT 0

#define KFPOLARSSL_ERR_AES_INVALID_KEY_LENGTH                                  \
    -0x0020 /**< Invalid key length. */
#define KFPOLARSSL_ERR_AES_INVALID_INPUT_LENGTH                                \
    -0x0022 /**< Invalid data input length. */

// Regular implementation
//

/**
 * \brief          AES context structure
 */
typedef struct
{
    int       nr;      /*!<  number of rounds  */
    uint32_t *rk;      /*!<  AES round keys    */
    uint32_t  buf[68]; /*!<  unaligned data    */
} aes_context;

#ifdef __cplusplus
extern "C"
{
#endif

    /**
     * \brief          AES key schedule (encryption)
     *
     * \param ctx      AES context to be initialized
     * \param key      encryption key
     * \param keysize  must be 128, 192 or 256
     *
     * \return         0 if successful, or POLARSSL_ERR_AES_INVALID_KEY_LENGTH
     */
    int kf_aes_setkey_enc(aes_context *ctx, const unsigned char *key,
                          unsigned int keysize);

    /**
     * \brief          AES key schedule (decryption)
     *
     * \param ctx      AES context to be initialized
     * \param key      decryption key
     * \param keysize  must be 128, 192 or 256
     *
     * \return         0 if successful, or POLARSSL_ERR_AES_INVALID_KEY_LENGTH
     */
    int kf_aes_setkey_dec(aes_context *ctx, const unsigned char *key,
                          unsigned int keysize);

    /**
     * \brief          AES-ECB block encryption/decryption
     *
     * \param ctx      AES context
     * \param mode     AES_ENCRYPT or AES_DECRYPT
     * \param input    16-byte input block
     * \param output   16-byte output block
     *
     * \return         0 if successful
     */
    int kf_aes_crypt_ecb(aes_context *ctx, int mode,
                         const unsigned char input[16],
                         unsigned char       output[16]);

    /**
     * \brief          AES-CBC buffer encryption/decryption
     *                 Length should be a multiple of the block
     *                 size (16 bytes)
     *
     * \param ctx      AES context
     * \param mode     AES_ENCRYPT or AES_DECRYPT
     * \param length   length of the input data
     * \param iv       initialization vector (updated after use)
     * \param input    buffer holding the input data
     * \param output   buffer holding the output data
     *
     * \return         0 if successful, or POLARSSL_ERR_AES_INVALID_INPUT_LENGTH
     */
    int kf_aes_crypt_cbc(aes_context *ctx, int mode, size_t length,
                         unsigned char iv[16], const unsigned char *input,
                         unsigned char *output);

    /**
     * \brief          AES-CFB128 buffer encryption/decryption.
     *
     * Note: Due to the nature of CFB you should use the same key schedule for
     * both encryption and decryption. So a context initialized with
     * aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.
     *
     * both
     * \param ctx      AES context
     * \param mode     AES_ENCRYPT or AES_DECRYPT
     * \param length   length of the input data
     * \param iv_off   offset in IV (updated after use)
     * \param iv       initialization vector (updated after use)
     * \param input    buffer holding the input data
     * \param output   buffer holding the output data
     *
     * \return         0 if successful
     */
    int kf_aes_crypt_cfb128(aes_context *ctx, int mode, size_t length,
                            size_t *iv_off, unsigned char iv[16],
                            const unsigned char *input, unsigned char *output);

    /**
     * \brief               AES-CTR buffer encryption/decryption
     *
     * Warning: You have to keep the maximum use of your counter in mind!
     *
     * Note: Due to the nature of CTR you should use the same key schedule for
     * both encryption and decryption. So a context initialized with
     * aes_setkey_enc() for both AES_ENCRYPT and AES_DECRYPT.
     *
     * \param length        The length of the data
     * \param nc_off        The offset in the current stream_block (for resuming
     *                      within current cipher stream). The offset pointer to
     *                      should be 0 at the start of a stream.
     * \param nonce_counter The 128-bit nonce and counter.
     * \param stream_block  The saved stream-block for resuming. Is overwritten
     *                      by the function.
     * \param input         The input data stream
     * \param output        The output data stream
     *
     * \return         0 if successful
     */
    int kf_aes_crypt_ctr(aes_context *ctx, size_t length, size_t *nc_off,
                         unsigned char        nonce_counter[16],
                         unsigned char        stream_block[16],
                         const unsigned char *input, unsigned char *output);

#ifdef __cplusplus
}
#endif

#ifdef __cplusplus
extern "C"
{
#endif

    /**
     * \brief          Checkup routine
     *
     * \return         0 if successful, or 1 if the test failed
     */
    int kf_aes_self_test(int verbose);

#ifdef __cplusplus
}
#endif

#endif /* aes.h */
